This invention relates to a jet loom, and more particularly to a method for injecting a transport fluid into a shed from auxiliary jet nozzles of the jet loom, wherein a weft thread is inserted into the shed by using the jets of injected fluid under pressure.
Generally, in a jet loom of such type, a main jet nozzle alone can not transport the leading end of the weft to a distance at a sufficient speed, so that a suitable number of auxiliary jet nozzles are provided on a reed to each produce a flow of air in cooperation with the main jet nozzle. However, if all the auxiliary jet nozzles are always operated, a great total consumption of air results. In order to reduce the total consumption, U.S. Pat. No. 3,705,608 has proposed to energize the auxiliary jet nozzles successively or in successive groups in time with the advancement of the leading end of the weft thread through the shed. Because each auxiliary jet nozzle is operated for the same period of time as the others, the injection timing of the auxiliary jet nozzles has to be adjusted when a transport speed of the weft is varied due to changes in thickness, kind of material and degree of fluffiness of the weft, and due to changes in operation speed of the loom. More specifically, in order to allow the weft to be effectively subjected to the function of the jets from the auxiliary jet nozzles, it is required that the injection timing of the auxiliary jet nozzles be advanced when the weft is transported at a higher speed and delayed when the same is transported at a lower speed.
Furthermore, even if weaving conditions are maintained unchanged, both the transport speed and the path of the weft will be subject to fluctuations each time a weft insertion operation is carried out, and the fluctuations will be gradually increased toward the end of one weft inserting operation. This causes the injection timing of the auxiliary jet nozzles to become out of time with the advancement of the weft leading end, thus resulting in the weft not being inserted.
It is therefore a principal object of this invention to provide a method for injecting a transport fluid into a shed from auxiliary jet nozzles, which requires no adjustment of the injection timing of the auxiliary jet nozzles even when weaving conditions are changed.